Convergence
by sueKay-04
Summary: NCIS/SG1/SGA Crossover. When an agent dies in bizarre circumstances at NCIS HQ, the Team must work with Homeland Security to find out the cause of his death, and to reveal a cover-up of shocking proportions...Set in NCIS Season 8 and Atlantis post season 5
1. Prologue

Hey there,

Well this is my first foray into NCIS Fanfiction, and it's a crossover with both Stargates SG1 and Atlantis! As this is my first time writing for the NCIS Team, I'll apologise in advance for any OOC behaviour...And if you notice anything OOC, please let me know!

Anyways...hope you enjoy this!

* * *

**NCIS Convergence**

**Teaser**

Ziva cursed quietly as she hit her head off of the underside of her desk. It had been a slow week, and the team had been case-less for four days so Ziva had decided to use her free time to clean out her desk.

"You okay?" Tim called over.

"I am just fine, McGee," she sighed before beginning to sort through the contents her drawers, now piled high on the desktop.

"Need any box files for your stuff?" Tim asked.

"Nope," she responded as an errant pen rolled off of the surface and back onto the floor. As she bent down to pick it up, she succeeded in hitting her head again. Hearing McGee's chuckle she sat up and levelled a glare at her colleague who quickly shut up and returned to his game of Solitaire.

Ziva heard the bang of the stairwell door and watched with amusement as Tony hopped into view.

"Wow, Tony...what did you do?" asked McGee as Tony ambled closer to the bullpen.

"It's my Skippy impression McGeek."

Tony continued hopping until he reached his chair. He sat down and quickly removed one of his shoes.

"Oh, sweet relief," he smiled as he tipped the shoe upside down, allowing the offending pebble to fall to the floor.

"Not for us," McGee said, waving a hand in front of his nose.

"Why did you not remove your shoe when you first felt the stone Tony?"

"I was in a hurry Zee-vah...there might be some _really_ interesting case for us to work on: messy crime scene; an interrogation or three; bad guys to arrest...Paperwork to file..." he sighed, replacing the shoe and slouching back in his chair.

"Where's Vance?" Tony straightened up when he heard Gibb's voice over his shoulder.

"Uhm..."

"I am not sure, I have not seen him."

"No idea, boss."

"Well Nobody's seen him, he's not answering his cell phone, and his wife says he left for work as normal this morning."

"Maybe it's on silent?" DiNozzo said, earning a stern look from Gibbs.

"Want me to find out where his cell phone is?" McGee asked.

Gibbs nodded and Tim quickly tapped on his keyboard, bringing up a tracer program. After inputting Vance's number the program triangulated his position.

"Well he's in the building."

"Where exactly?"

"In the elevator."

"The elevator's out of order," said Tony.

"Yeah I noticed that as I walked up the stairs this morning DiNozzo," Gibbs stated as he began dialling Vance's number and walking in the direction of the elevator. Tony, Tim and Ziva got up and followed their boss and as they drew closer to the elevator, they could hear the ringing of Vance's phone.

Gibbs snapped his phone shut, and called through the elevator doors, "Vance?".

No answer.

"Call maintenance...We need to get this door open."

"I already called them," said a young agent from another team, as a crowd began to gather near the elevator. Within seconds a technician appeared with the key and opened the doors enough to allow Gibbs and DiNozzo to force them apart. After a few seconds the doors were open, and the team surveyed what they had found.

Vance was out cold, propped up against the right-hand wall of the elevator, and had no visible injuries. On the other side lay a skeletal figure, who was facing away from the team and appeared to be wearing a smart business suit. As Gibbs checked the Director's pulse, Tony tapped the prone form. When he got no response he slowly turned the man onto his back, and recoiled in horror at what he saw...

A completely desiccated corpse...


	2. Chapter 1

Hi there,

Apologies for not uploading this sooner! I've been having a lot of trouble with writer's block again, and I'm still getting used to writing for these characters, so I've reworked this chapter a bit...Still not 100% happy with it, but it's as good as it's going to get!

For the record I know nothing about DNA, so please take the stuff about DNA in this chapter with a pinch of salt!

Enjoy!

* * *

**Chapter 1**

Ducky and Jimmy stared at the corpse which now occupied the NCIS morgue.

"Oh my dear boy, what did you get yourself involved with?" Ducky sighed, "such a pity, but we'll find out how this was done to you and you'll know yourself that Gibbs won't rest until he's found you killer."

"I...I've never seen anything like this Dr. Mallard," said Jimmy, slightly flustered, "I mean...for his body to have gotten into such a bad condition...it takes months not hours!"

"It took three hours," Vance grunted from the next table, clutching at his throat with one hand and the back of his head with the other. "I came into work as normal, got into the elevator with Agent Danes and that's when the the elevator stopped and the lights went off...I heard a scraping noise overhead and I heard Danes yell...Next thing I know he's in a body bag and I'm staring Gibbs in the face."

Vance sighed loudly, wincing as his headache moved up a gear. As he began to get to his feet, Jimmy began to protest.

"I'm sorry Director, but you really shouldn't be walking about."

"Director Vance, please remain seated," Ducky chided as he walked over to the younger man, "You have very nasty concussion and you're only lucky that I haven't sent you to Bethesda yet."

"He's only lucky he's not at Bethesda because we still need his statement, Duck," Gibbs stated as he strode into autopsy.

"What have you got?"

"Not a whole lot I'm afraid...I am absolutely stumped...If I didn't know any better I'd said Agent Danes died approximately seven months ago, but seeing as how I saw him two days ago and seeing as how he signed into work this morning, that obviously cannot be the case."

Gibbs merely stared at Ducky as Vance came and stood next to them.

"Of course, there is this rather bizarre depression in the victim's chest, and a lot of smaller welts and cuts...The marks seem to form the imprint of a rather large clawed hand...Most disturbing, but also very intriguing...It reminds me of an old case in Guatemala about a -"

"Thank you Dr. Mallard," Vance cut the ME's story short.

"Yes well, I've taken some samples from the wound to determine if there is any DNA from his assailant...Abby is performing the analyses just now."

Vance nodded, "Thank you...I'm going to have to write my report now Doctor," before turning to leave the room.

"Director!"

"Don't worry Ducky, I'll make sure he goes to Bethesda when he's done," Gibbs reassured, appeasing the Scotsman.

* * *

"Can't believe T2's gone," sighed Tony.

"T2?" quizzed Ziva.

"Yeah...Timothy Danes...He was the McProbinator mark II...and a big movie fan."

Ziva gave her partner an odd look.

"He's talking about the Terminator Ziva," McGee began to explain before thinking otherwise, "Oh nevermind."

"Who could do that to someone so quickly?" Tony said with exasperation, "I mean what...There's nothing I can think of that could do that to a body outside of time itself."

"I'm sure Abby, Ducky and Jimmy will have something for us soon," Tim responded, but not sounding all that hopeful.

* * *

Abby screwed her face up at the results on her computer monitor and picked up an empty Caf-Pow container. This didn't make any sense! With the large handprint in Dane's chest both she and Ducky were highly hopeful of finding the assailant's DNA in the wound.

She'd found DNA alright, but DNA of what?

Hearing footsteps behind her she playfully snapped, "You're late, mister."

The footsteps became softer, and a Caf-Pow-holding hand appeared from the right.

"What have you got Abs?"

"A whole lot of nothing, that's what," she sighed dejectedly, "I mean I've got a whole lot of data that would probably form every cryptozoologist's dream...The DNA in the wound isn't on record."

"So widen the search."

"Didn't you hear me Gibbs? I said this is every _cryptozoologist's_ dream! I didn't mean the attacker had never been in the databases I was searching...I mean the DNA isn't human, and isn't on record...I have no idea what attacked Danes and Vance!

"Now although we've only completely mapped the human genome and we've only partially mapped the Chimpanzee genome...We know that every living thing on this planet has DNA in one of three conformations: A, B and Z, and only B and Z are found in functioning organisms. This DNA...It's totally different...If I were a conspiracy theorist...I'd be thinking the aliens are getting ready to invade...There is nothing alive on this planet that compares to the DNA we got from Dane's wound."

Gibbs blinked. He barely knew a thing about DNA, but he clearly understood what Abby was telling him.

"There's more though," Abby said before picking up a small vial from her workbench, "Ducky syringed this out of the wound and asked me to analyse it. It's some sort of enzyme Gibbs, made up of the DNA I found from the wound, but also with faint traces of human DNA. The DNA isn't Danes or Vance's and it isn't on any database. The question is, what animal or...thing, could make an enzyme infused with human DNA, and why?"


	3. Chapter 2

Hi all!

A thousand apologies for leaving you all hanging. Unfortunately I lost the original copies of this chapter and the next few, and there's nothing I hate more than rewriting things. However, that's what I've had to do!

Many many thanks to Aussie-mel, Rittanicus, Pink Wolf Princess, Juxi, CheveronChick, Stina Whatever, VeerleTarjaFreak, ManicTater, Panglossian, stargatechick11, MuseUrania, remerkaba, dreameralways, Nedy Rahn and Enilas for the reviews! And thank you to everyone who's added this story to their watchlist and/or their favourites!

dreameralways - Thank you for the offer! I don't think there'll be much of a technical aspect to the story (there's a reason I did Social Sciences and not anything scientific, lol!) but I'll keep your offer in mind :)

Panglossian - NCIS - S7/S8, SG1 - Post Continuum, SGA - Post S5 :)

Stina Whatever - SG1 will be involved throughout, but yes, this is team Sheppard's speciality!

CheveronChick - Scotland is part of Britain so Ducky is both Scottish and British, however most Scots identify as Scottish first and British second :)

* * *

**Chapter 2**

"Absolutely not!"

"But Director!" Abby protested, "We need to bring in an expert. The case is at a complete standstill. Gibbs' teams needs to know what the mystery DNA is before they can continue with the investigation. Ducky, Jimmy and I do not have the expertise to figure this out...we're not geneticists."

"Abigail is right Director...We need to bring in someone to help with this investigation."

"The answer is no," Vance sighed, "We're a Federal Agency...word gets out about this and the Navy Yard will be crawling with UFO fanatics by the end of the day. Not to mention that the agency will be a laughing stock."

"But Director! I believe this DNA is alien-" protested Ducky.

"-And this alien nearly killed you!" Abby pointed out, "and it _did_ kill Timothy Danes...We owe it to him to find out what happened! You're worried about some UFO nuts bringing NCIS into disrepute? What about us not finding the killer of one of our own, when the murder happened in our own damn building!"

Ducky flinched, surprised to hear Abby using even a mild cuss-word.

Vance sat back down at his desk, "Who do you want to bring in?"

"A friend of mines, an MD who's also a geneticist. His name's Dr. Carson Beckett and he's currently teaching at the University of Colorado Health Sciences Centre. We can trust him...I can send him our raw data."

"Tell me a bit more about this Dr. Beckett."

"Ah, young Carson," Ducky smiled, "Met him once about a decade ago at an Alumni Association meet at Edinburgh Medical. Highly capable young man, I knew he'd go places."

"He British?" asked Vance.

"Yes. Brought up near Glasgow I believe."

Vance looked away from the pair, shaking his head.

"If Dr. Beckett's nationality is going to be an issue, need I remind you that I too hold a British Passport?"

"He's been living in the States since 2003," interjected Abby.

Vance now clasped his hands, his jaw working overtime. After a moment he opened one of his desk drawers and pulled out a toothpick. He began to chew on it, seemingly working through his options.

"Send him your data Ms Sciuto."

* * *

"Well?" Gibbs asked as Abby and Ducky arrived in the bullpen.

Abby looked around at the team and also at Jimmy, "I've been given permission to pass what we know onto a friend of mines in Aurora, Colorado."

"Who knows, we might actually figure out this case now," Gibbs said, turning and heading for his desk.

* * *

Shortly after sending her data to Dr. Beckett she heard back from her friend.

"_Hello Abigail,_

_It's wonderful to hear from you! I regret not being able to come and visit you recently. I've been very busy with some very exciting projects that I hope I can tell you about soon! I'm relieved that you heard that the rumours of my demise were greatly exaggerated! I have had some health issues which have been resolved, and I am very much alive. I have had a wee look over your data – interesting stuff! - and I will try and get back to you as soon as I can._

_Take care,_

_Carson"_

However, after the email there had been silence. One day had turned into two, then three.

It had been a strange few days as well. Danes' mother had lost it when she'd come to see her son. Ducky had advised her that she would be better remembering him in life, and not in death so as to spare her the pain of seeing his dessicated remains. Claudia Danes had been angry at his decision, and had been furious when she realised they'd had no idea who had killed her only son. She'd launched herself at Vance, and had needed to be restrained by Gibbs who had managed to calm her down, vowing to find her son's killer. That promise had stopped her from continuing her attack on Vance, but her lawyer had since been in touch and the family were now threatening to sue the agency.

Vance himself had been acting rather odd, almost as if he didn't want NCIS to be investigating what had happened. Gibbs was barely being civil to Leon, and Abby knew their boss' gut was telling him things he hadn't shared with the team yet. Abby was growing suspicious of Vance too, but Ducky assured her that his odd behaviour stemmed from his shock at the attack, and his own guilt at loosing an agent literally from under his nose.

Abby was shaken from her reverie by soft footsteps, and a Caf-Pow was clunked down in front of her.

"Talk to me Abs,"

Abby couldn't help but grin when he said that, but her face fell moments later, "But I don't have anything for you! I can't accept the Caf-Pow!"

"That is for you, not for your work. Talk to me."

Abby took a sip of the caffeinated beverage, "I don't know why he hasn't gotten back to me...Maybe he's snowed under with his students, or his own research, but Carson is like the politest person on the planet! I would have at least expected him to drop me an email telling me why he hadn't looked at my data."

"Do you trust him?"

"Of course I do!"

Gibbs grinned, "Then he'll come through for us."

Gibbs placed a quick kiss to her temple, and then turned, heading back to the bullpen.

* * *

"Anything?" Tony asked as Gibbs sat at his desk.

"Nope."

Tony slammed an open palm hard against his desk, "I can't believe this. He's one of our own Gibbs...And we're getting nowhere."

The team vaguely heard the elevator, but they were too wrapped up in their own recriminations over the lack of progress on the case to pay attention to who had arrived in the office.

Tony's eyes were fixed at the ground, but he was the first to become aware of their visitor as a long, shapely pair of legs entered his field of vision. His eyes travelled up, meeting the attractive face of a blonde Air Force Colonel.

"Agent DiNozzo, I presume?" she smiled.

"Air Force?" he said, drawing the attention of the rest of the team. Gibbs automatically rose to investigate the new arrival.

"If you're looking for AFOSI you're definitely way off the mark Colonel."

"AFOSI?" asked Ziva.

"Air Force Office of Special Investigations," Tony clarified.

"I'm not looking for OSI, Agent Gibbs. I'm here on behalf of Homeland Security as we're going to be leading the investigation into the death of your Agent."

Gibbs drew his head back a little at her statement, his eyebrows raising in both surprise and indignation.

"Excuse me? He's _our _Agent. This is our investigation. You're Air Force, this is the _Naval _Criminal Investigative Service. You have no jurisdiction here."

"On the contrary, she does," said Vance from the mezzanine level.

"Leon!" Gibbs barked.

"I don't like it anymore than you Gibbs, but she's here on behalf of Homeland Security. Secnav's orders are to cooperate fully."

Gibbs growled, looking back the Colonel, "Okay...What's you're plan of action?"

"Perhaps we should be properly introduced first," Tony interjected, "I'm Special Agent-"

"Anthony DiNozzo, I know. Special Agent Leroy Jethro Gibbs, Special Agent Timothy McGee and Probationary Agent Ziva David," she smiled at each of them in turn, "Colonel Samantha Carter."

She extended a hand to Gibbs, "It'd be much easier if we could work together on this."

Gibbs however did not offer his hand, instead he fixed her with an angry glare. Carter chewed on the inside of her mouth and let out a sigh.

"My plan of action is to bring in my own people to work the scientific angle. I'm afraid Doctors Mallard and Sciuto are off the investigation, as is Jim Palmer."

"No," Gibbs stated.

"I have my orders."

"Damn your orders. He's our agent. He died on our turf. It's _our_ responsibility to find his killer!" Gibbs tried to keep his temper.

"Perhaps we should continue this conversation in private?"

"I don't think so-"

"I insist," she replied calmly, an increase in her blinking the only sign her patience was being tested.

"Fine. My office, now," he snapped, stalking off in the direction of the nearest elevator.

"Hmm...this case just got a whole lot more interesting," Tony beamed.

Ziva and McGee just tutted at the SFA and continued their previous waiting game.

* * *

Carter got into the elevator and watched Gibbs press a button for one level up. She was rather surprised moments later when Gibbs pulled the emergency stop.

"Agent Gibbs?"

"Welcome to my office," he said sarcastically.

"Oh."

"I need you to be straight we me Colonel. What the heck gives you the right to be in charge here? The Navy and the Marine Corps deal with their own crimes. The Air Force deals with theirs. What's so special about this case?"

"We intercepted the data Dr Sciuto sent to Dr. Carson Beckett, and we've seen those DNA results before. This is an area of expertise for my people."

"But I doubt you're a geneticist, Colonel."

"And you'd be right. I'm a theoretical astrophysicist."

"Which makes you even less qualified than Abby or our MEs."

"You would think."

At that moment Carter's pager beeped and she checked the message, a quick look of satisfaction crossing her features.

"If we're going to work together on this, you're going to have to give me reassurance that you really want to catch Danes' killer. If the DNA results are just for some project you've got going on, or you're angling for research funding, I don't wanna know, and I'll make sure you're out of this building by the end of the day...I need concrete proof you know what you're doing, and a concrete reason for me to hand this over to you."

"Luckily for you I've just been given permission to read you in. You need to know the stakes...This is a matter of national security."

Gibbs drew her a wary look.

"You're going to have to trust me Agent Gibbs...I can read you in, but you'll need to give me your firearm, and your hand."

"There's only one way you'll ever get my Sig – by prising it out of my cold dead hands."

"I'm afraid it's not optional. Give me your gun, and you get read in. Refuse? Then we do this without you, and you may never find your killer. If you're concerned about giving me your weapon, you shouldn't be. I'm currently armed, and if I wanted to kill you or injure you, I'd have done so already. And if you need more proof," she reached into her pocket, pulling out a leather wallet, "here's my ID."

Gibbs gave her another look, "How did you get through security with a weapon?"

"It's government issue, and my orders were signed by your former director."

That explanation appeased Gibbs, and after a moment he emptied his Sig, handing the now empty handgun to Carter.

"You never said I wasn't allowed to keep my ammunition," he said.

"Ammunition's not a problem," she smiled calmly, "now give me your hand."

"This better be good Colonel."

"Call me Sam."

"Sam..."

Seconds later she produced a small device from another pocket, and before Gibbs could jerk his hand away, she pressed a button, and Gibbs was overwhelmed by a blinding light and an almost ticklish sensation on his skin. He screwed his eyes shut, hoping for the feeling to disappear fast, and it did. Tentatively he blinked, before fully opening his eyes once again.

And Gibbs could barely believe what he was seeing...


	4. Chapter 3

Hey all!

Here's another chapter!

Many many thanks to writergirl99, Chris7221, Bookworm37, PatriciaS, remerkaba, VeerleTarjaFreak, Laura17, Stina Whatever, Mrs Derek Morgan 1995, CheveronChick, Rebel Magnus, Enilas and Nerdy Rahn for the reviews!

Chris7221 - Thanks for the feedback on the science. Unfortunately I know zip about science, so I'm just trying to muddle through best I can!

Bookwork37 - Apologies, but there is the whole Stargate back story thing in this chapter for the benefit of NCIS fans who aren't familiar with Stargate.

I wrote this chapter back at the start of November, but life has been getting in the way! Gibbs may seem a little OOC in this chapter, but who really knows how they'd react if they were in this situation?

Anyhoo, enjoy :)

* * *

**Chapter 3**

Gibbs closed his eyes, and shook his head before once more daring to look at the view from the window in front of him.

"Is...is that?"

"Earth? Yes...We're currently in geosynchronous orbit above San Francisco...Welcome aboard the USS General Hammond."

As Carter welcomed him on-board whatever they were on-board he began to back away from the massive window in front of him, his heart beginning to race.

"That's...That's space...We're on a _spaceship_?"

He again risked looking out into the star-studded abyss and down to the planet below and then took in his surroundings.

The window he stood at must have been 15 feet by 20 feet, and the room was painted in shades of grey - every inch was metallic panelling. Colonel Carter and an Airman stood behind him, monitoring his reaction. Behind them was some sort of workstation, and behind that he could see down a corridor where more airmen and officers were walking about.

"This is the General Hammond, one of a fleet of Daedalus class Battle Cruisers that are jointly operated by the Air Force and the Marine Corps. Britain, China and Russia also have their own fleets and all are used primarily for deep space exploration."

As Sam talked Gibbs felt an odd, almost itchy sensation travel through his skin. Moments later he felt his face flush and he suddenly felt very queasy. Sam's voice barely registered as he was overcome by a wave of dizziness. Was he having a bad reaction to the teleporter, or whatever-it-was that had gotten him into space?

He answered his own question as he dropped to the ground, hugged his knees to his chest and yelled "Get me outta here!"

* * *

"A panic attack?" Gibbs said quietly.

"Aye...it's not uncommon," said a doctor with a distinctly Scottish accent, "Colonel Carter brought you in a few minutes ago, but you calmed down as soon as you got into the medical bay and away from that big window."

Gibbs felt his face flush again, "That's never happened to me before...I don't get panicked."

"The body fights what's unnatural...It's why so many people get motion-sick, and why so many are terrified to fly. Perhaps space is your limit? We've diagnosed quite a few space phobias since the Stargate Programme came into existence, believe me!"

"I don't have phobias," Gibbs stated, leaving no room for argument.

Catching Colonel Carter wearing an amused smirk he levelled a glare at her. For her part she quickly hid the smirk, returning his glare with a serene and disarming smile.  
"Special Agent Gibbs, meet Doctor Carson Beckett."

The doctor smiled, extending a hand to Gibbs, but Gibbs merely turned his glare on the MD who swallowed his own introduction instantly.

"Abby was counting on you," Gibbs said simply and Carson had the good grace to look at the ground.

"I've yet to let her down," he responded soberly, "but on examining the DNA profile she sent me, I had no choice...I had to inform Stargate Command."

"Star-what?"

Carson shot Sam a worried glance, "He has been read in, hasn't he?"

"If he hadn't freaked out just now, he would have been," Sam grinned.

Gibbs drew her a look, realising that for all her book-learned intelligence and her calm, demure disposition, at her core there was a devilment in her, not all that far removed from that of his own senior field agent.

"I'll ask again. What the heck is Star...Command?"

"Let's take a walk," Sam smiled.

"Just keep him away from any viewports," Carson helpfully reminded them.

* * *

A few minutes later Gibbs and Carter were walking down one of the corridors aboard the General Hammond. Gibbs was eyeing every passing crewmember, taking note of their patches. Some had one that said "USS GENERAL HAMMOND" while others wore that and another saying "F-302", which Gibbs was assuming belonged to some classified Air Force fighter jet.

His curiosity had not gone unnoticed by Carter, and he looked at her for an explanation. She merely smiled for the umpteenth time before launching into a story.

"In 1928 an archaeological team working on the Giza Plateau in Egypt uncovered a bizarre artefact, unlike anything that had previously been found anywhere in the world. It was a giant ring of metal inscribed with 36 hieroglyphs. The ring measured eighteen feet across and the hieroglyphs appeared to be completely unique-"

"I get enough rambling lectures from my ME, Colonel."

"There's a point to this one, if you'd let me continue."

Gibbs merely quietened, allowing Sam to talk.

"There was no reference to the ring or its purpose anywhere in Giza, or anywhere else in Egypt for that matter, and after being shipped to the United States, it was ignored - at least until World War II.

"The Army ordered research on the device as we entered the War, believing the ring to be a weapon. They were wrong, and stopped their experiments on the device in 1945 when they believed the device had killed one of their scientists. The tablet and the device were once again stored until Vietnam, when the ring was moved to Colorado Springs. The tablet itself became lost.

"No more research was carried out on the device until the late eighties, when the daughter of the Egyptologist who had found the artefact was given complete access to the ring for research purposes. She opted to have it transferred to Cheyenne Mountain for analysis. Tests indicated that the ring was made entirely from a previously unknown metallic element which we now call Naquadah, and in 1994 Doctor Daniel Jackson discovered the Hieroglyphs actually showed star constellations. Shortly thereafter we were able to mobilise a reconnaissance unit that finally revealed what the device was created for - to allow instantaneous transport between planets through use of artificial wormholes. The device was then known to be called a Stargate, and since then we have sent teams to literally thousands of worlds across several galaxies, and have made contact with hundreds of alien species and human groups that have populated some of those worlds."

Gibbs stopped in his tracks, and turned to level an incredulous look at Carter.

"You're trying to tell me that for well over a decade we've not only been sending people into space with relative ease, but we've also been going to other planets, and making contact with aliens?"

"Yes."

"And there are humans living out there?"

Carter nodded, "The Stargate was created by a race we know as the Alterans. They're referred to in history as the Ancients-"

"The Great Builders?"

Sam spun to look at Gibbs, giving him a wide smile.

"Just because I'm a Marine doesn't mean I've never read a history book," he said by way of an explanation.

Sam's smile turned into a grin, "Yes. The Ancients were the Builders of Roads, the roads being Stargates...Unfortunately the Ancients were afflicted by a plague ten million years ago, and most of them left our Galaxy. What was left of them either died, or they achieved Ascension, something we'll tell you all about shortly.

"In the power vacuum that was created, another species stepped in - the Goa'uld - and they harnessed the Stargate system in order to enslave the peoples of the worlds with Stargates on them. The Goa'uld are a parasitic species, and they soon found that humans made excellent hosts for them, so they captured large numbers of humans and took them to other worlds to establish empires. The members of the Goa'uld that did this became known as the Gods, and are known to us today as the Egyptian Gods."

"Like Ra, Apophis, Osiris?"

"Exactly. In fact I met both Apophis and Osiris many times...They were enemies that we managed to eliminate."

Gibbs rubbed his face with his hands. He was having trouble believing what he was hearing.

"I know this is a lot to take in Agent Gibbs, but you'll soon see everything I've told you is true. But what you need to know is that the Goa'uld were not the sole threat we've encountered - there are others that are far more powerful and far harder to stop. Your Agent Danes was a victim of one of these enemies."

As the pair passed a small viewport, Gibbs looked away, his stomach reminding him of his unease at being in space, and his gut realising that Ducky and Abby had been right.

"He really was killed by an alien?"

"Unfortunately yes. The only words of comfort I can give you is that Agent Danes' death would have been quick."

"But not painless."

Sam blinked again, biting the inside of her bottom lip, "Unfortunately it would have been anything but painless. Your agent was killed by an alien known as a Wraith. They are large and vicious and extremely intelligent, and they feed on humans - they quite literally need our life force to survive."

"You're saying this 'Wraith' ate Danes?"

"For lack of a better word, yes."

Gibbs shook his head, trying to shake off the horror of the young agent's demise.

"The Wraith are able to hide from just about every type of sensor we have, and are able to create personalised cloaking devices that hide them from our field of vision. They are heavily armed and one was once shot thirty-two times and survived - They are extremely hard to kill, and conventional kill shots normally won't even incapacitate them.

"Their weaknesses however, are their motives. Over the course of the last ten thousand years their feeding process has forced their DNA to adapt and include human characteristics, including some of our behaviours. Other than their feeding habits, their behaviour can be disturbingly human. Some do what they do to survive. Others get perverse pleasure from feeding. Others need power. Some acknowledge their 'prey's' worth, others merely see us as a food source. However they also have a militaristic outlook and are at war with other groups, other hives. And what we need to do is figure out what this particular Wraith's motive was."

"Any theories?"

"We have a couple. For starters, we didn't even know that there was a Wraith on Earth...Wraith do sometimes operate independent of a hive, and when they do that they're normally very good at escaping detection and gathering intel. There is currently a large ship of Alteran origin holding position about three hundred miles off the coast of San Francisco. The Wraith may have been at the Navy Yard to gather intel about ship movements in order to find a way to the Alteran ship, and then off the planet.

"Second theory - he may have been at the yard to find out about ship movements, but may have been working as part of a team.

"Third and most disturbingly - a remnant of the Goa'uld called The Trust operates on Earth today. As I told you the Goa'uld use humans as hosts and literally take over their bodies. This obviously gives them the ability to hide in plain sight. It is possible that this Wraith may be working for them, but it is highly unlikely."

"Can't say those theories fill me with confidence Colonel," Gibbs said soberly, "And you're certain it was one of these Wraith that killed Danes?"

"Positive. Their...modus operandi is completely unique. I'm assuming your ME found a large hand print on his chest full of welts and an enzyme of some sorts?"

Gibbs nodded, "So definitely a Wraith?"

Sam sighed and grew quiet, but Gibbs had another question.

"So why didn't this Wraith kill our Director?"

* * *

Gibbs spent some time touring the General Hammond, taking in views from the bridge (all the while trying to remain nonchalant about it to keep the feeling of panic at bay), the F-302 hangars, the engine room, the Asgard room and the science labs. He'd also been given a schedule of talks to attend both on the Hill and at Cheyenne mountain at a later date to gain more insight into the programme's history.

"You're lucky - when I started with the programme we knew literally nothing about what was out there...We just stepped on through the Stargate and hoped we'd find something interesting on the other side...What I wouldn't have given for a welcome pack," Sam quipped.

"So everybody gets thrown in at the deep end?"

"You could say...A leader of one of our former off-world operations, project Atlantis, was instructed to visit the White House. Once there she was left in a room piled high with mission files and told to read them - no explanation, no reassurance. She read through all the nitty-gritty details for hours, before President Hayes offered her a job which he made clear she couldn't turn down. A day later she was installed as head of the Stargate Programme, before transferring to the Atlantis project."

"That's a pretty quick turnaround," Gibbs remarked before continuing, "so what's your plan for catching this Wraith, and when does my team get taken into the fold?"

Sam began to talk when Gibbs' attention wandered as a Hebridian scientist walked by them.

"Dr McCulloch," she called to him, "I'd like you to meet Special Agent Gibbs, he's new to the programme."

"Agent Gibbs, it's a pleasure!" said the reptilian alien, extending a hand to a stunned Gibbs.

"McCulloch?"

Dr. McCulloch pointed to himself and looked at Carter, "Am I his first alien?"

"That he's aware of, yes," Sam winked at him before turning to Gibbs, "Zenet's onboard as part of a personnel exchange. We don't share technologies but we help each other to improve technologies we already have. Our own Dr. Zelenka is currently working with scientists on Hebridan to the same end."

"It's very rewarding," smiled McCulloch, "Your planet's beautiful, and it's been nice to see where some of my fellow Hebridians came from originally," McCulloch smiled politely, "I'd love to stay and talk awhile, but Dr. Kavanaugh needs me in the Asgard room."

The alien inclined his head before continuing down the corridor.

"McCulloch?" Gibbs said in disbelief.

"Zenet McCulloch is from the planet Hebridan, a planet with dual populations of Humans and Serrakins. The humans were captured from the Outer Hebrides of Scotland and the Serrakins were captured from another planet the name of which is still unknown. After they deposed their Goa'uld oppressor, the two races surprisingly managed to work together, and they're now one of our closest allies. Dr. McCulloch has some human ancestors, hence the surname."

"So humans and aliens can...y'know."

"Yes," Sam answered the silent question, a bemused grin on her face.

"Okay."

The pair continued their walk, arriving in the messhall. A quick order of black coffee and blue jello later, they sat in the small room, with Gibbs trying to ignore the view from the window.

"Anyway, about my team."

"We assess them throughout this investigation, and if they make the grade, they'll be given full disclosure for the programme."

"But not knowing about the programme will hinder the investigation-"

"That's why we'll be bringing in our own people as well. General Jack O'Neill from Homeland Security - which is actually called Homeworld Security - Dr. Daniel Jackson, Colonel John Sheppard, Dr. Rodney McKay, Teyla Emmagan and Ronon Dex will likely have already arrived at the Navy Yard. They're some of our best people, and they'll be dealing with the more sensitive information."

"I don't like it," Gibbs said definitely, "leaving my people in the dark and bringing in Air Force Officers and Personnel is going to cause a lot of problems. Too many cooks and all."

"That's the best deal we can give you. The alternative would be Homeworld Security and the Stargate Programme taking over complete control of the investigation. Take it or leave it, that's our offer."

Gibbs took a large mouthful of coffee, thinking over his limited options.

"It's a deal, but you'll realise pretty quickly that my people can handle...this," he gestured towards the window, "and that they'd be an asset."

Sam smiled, "I think you're right, but it's not that simple...However I can tell you that Dr. Beckett had already put Dr. Sciuto's name in for consideration for a position within the programme many years ago. Part of the reason she's off the investigation is to allow our people to do some background checks on her, and if she checks out, she'll be read in by the end of the week. And for what it's worth, I think our people will work well together...I'm sure you and General O'Neill will get on swell," she grinned.

Gibbs was highly sceptical of that comment, but resisted commenting, downing the rest of his coffee in one fluid motion. Carter had already finished her jello.

"You're wanting to go back to NCIS?" She said.

"I've been gone a while...someone might need that elevator," he gave Sam a small grin.

"Alright then," she smiled in response, retrieving the transportation device from her pocket.

"One thing though, what did you mean when you said McCullough was the first alien I was aware of meeting?"

Sam let out a little giggle, "You'll find out."

A moment later they were back in the NCIS elevator. Gibbs quickly flicked off the emergency switch, and moments later the pair strode back into the bullpen.


	5. Chapter 5

Hi all!

Many many apologies for the length of time it's taken me to update this story, but any motivation I've had for writing of any kind took an extended leave of absence!

Many thanks to Jiltanith, EvE79, Some101, OCMichael, Soten-ni-zase, middream06, Artemisbeloved, The Queen of Confusion, sparra-music, Dreamer22, writergirl99, Madances, Bookworm37, rebelmagnus, Trife, Chris7221, FreakyLeo88, scifi-karis, FraserMage, Alkeni, kellyh59, Nedy Rahn, remerkaba, Mrs Marcus Volturi, and everyone who's messaged me about this story for their reviews and feedback!

As it's been years since I last touched this story, I thought I would clarify when it is set.

NCIS - Beginning of season 8

SG1/SGA - Post movies and series 5.

This is another exposition filled set-up chapter, and something of a necessary evil...The story will start to move along after this chapter! :)

* * *

**Chapter Four**

Gibbs and Carter walked out of the elevator to find workman peering back at them intently.

"Boss!" Tony called out, "You okay?"

"Yeah, why?"

"Well you and the Colonel here were stuck in that elevator for a while, and when we couldn't raise you," he pointed at his phone, "...we got a little worried."

"Your boss and I were just having a little chat," Sam smiled, "and we've reached a deal."

* * *

"Gibbs! That is _so _not fair! How could you do that?! I'm not talking to you. That just sucks! I'm so angry!" Abby shouted.

"Abs-"

"I mean seriously! Me, Ducky and Jimmy are all off the case for Colonel Pretty over there?!" Abby glowered in Sam's direction before stalking off into a corner muttering, "I'm gonna kill Carson."

"This was the only way," Gibbs reasoned, feeling anger radiate from his favourite, and betrayal from his two MEs.

"I wish we could explain further, but this is a matter of National Security and a lot of what we will be dealing with is 'need-to-know', and at present you don't." Sam added.

"Some way to run an investigation," Tony spat, with Tim nodding and Ziva glaring in agreement, "Gibbs, this is a million times worse than Domino, and that was bad enough...This whole thing stinks of a cover-up."

"I agree," Ziva said quietly.

"It was out of my hands," Gibbs sighed, "it was either that or relinquish the case to Homewo-Homeland Security entirely."

Sam winced as she realised Gibbs had very nearly said Homeworld Security, but pressed on with their explanation.

"You'll be working with the best of our people, and I hope you'll put jurisdictional anger to one side because I'm sure you'll all work together very well.

Your main point of contact will be Lieutenant General Jack O'Neill - my former CO. You'll also be working with Dr. Carson Beckett, Dr. Daniel Jackson, Dr. Rodney McKay, Colonel John Sheppard, Ms Teyla Emmagan, and Specialist Ronon Dex."

"Rodney McKay?" Abby said, "That arrogant slimeball?"

"What is Ronon Dex's specialism?" Tim enquired upon seeing an unreadable look cross Sam's features.

"Classified…And McKay might be arrogant, and more than a little whiny, but he's no slimeball," Sam responded to both Tim and Abby's comments with a faint smile, "My people will be arriving shortly, so I hope we can all work well together."

* * *

Tony paced the bullpen tutting and sighing as he went.

"Must you do that?" Ziva groaned, leaning back in her chair.

"Pray tell, Miss David, exactly what I should be doing at this moment. Our 'supervisors' will be here shortly to hold our hands through the rest of case. I need to contain my excitement!" he spat sarcastically.

"It could be worse Tony," McGee advised, "they didn't kick us off the investigation and given Vance's attitude earlier, that could have been on the cards. They fact that they _didn't…_well I think it means they know that they might need us."

"I don't like being maybe needed, I like being _essential_ to my work…It's a personal pref-oh, wait."

Tony stopped pacing and jumped back to his desk as a group of people emerged from the elevator and walked towards the team. Carter, Gibbs and Vance arrived in the squad room from the opposite side of the room. Sam strode forward and an Air Force Lieutenant General met her in the middle of the bullpen.

"General O'Neill," Carter began, "I'd like to introduce you to NCIS Director Leon Vance. Director, this is General Jack O'Neill, head of Homeland Security."

McGee's eyes widened and he shared looks with Ziva and Tony. This was big.

"It's an honour to meet you again Director Vance, I only wish it were under better circumstances."

"Likewise sir," Vance said, extending a hand to the older man, "If everyone would like proceed to MTAC please," he said eyeing the rest of the assembled group.

A minute later both the NCIS and SG teams shuffled into MTAC, taking seats as instructed, both teams sitting unconsciously segregated on opposites sides of the centre. Jack waited for a moment to catch their attention before they began.

"I'm sure you all heard my job title, so I'm assuming you'll all know that this case is a matter of National Security. Unfortunately due to the nature of this investigation there is a lot of information that we will be unable to share. We are hoping that this will change in the near future but we'd like to ask that you remain patient in the meantime. Also I think it would help if we all knew everyone's names and job titles, and I think we'll start from the left!" Jack took a seat on a nearby computer chair and began to swing back and forth absent-mindedly.

McGee looked to his left and realised he was to go first.

"You don't have to stand up," Jack said with a hint of both sarcasm and humour.

"Uhm…Okay…I'm Special Agent Tim McGee…I'm a computer forensics expert and I've been a member of the Major Case Response Team for six years."

"I'm Probationary Agent Ziva David and I'm a former member of the Israeli Mossad. I've been on Gibbs' team for five years."

"I'm Very Special Senior Field Agent Anthony D. DiNozzo," Tony began using his 'full title', "I'm a former homicide detective and I've been on Team Gibbs for nine years."

O'Neill smiled in DiNozzo's direction knowing a 'kindred spirit' in terms of sarcasm when he saw one, before looking in Gibbs' direction.

Gibbs raised an eyebrow before sighing and rolling his eyes as he realised he too would have to introduce himself.

"I'm Supervisory Special Agent Jethro Gibbs. I'm a former Marine Gunnery Sergeant and MP. I've been with NCIS for 17 years, and I've headed up the Major Case Response Team for nine years."

"Thank you," Vance deadpanned, looking at Gibbs.

"Okay kids," Jack smiled in the direction of his own people.

"I'm Colonel John Sheppard, I'm attached to Homeland Security and I've been in the Air Force for over twenty years."

"I'm Colonel Samantha Carter. I'm a Theoretical Astrophysicist formerly attached to NORAD and now with Homeland Security."

"I'm Dr Daniel Jackson and I'm an anthropologist and diplomat and I've been working with the military for a number of years."

"I'm Dr Rodney McKay, I'm a Mechanical Engineer and Physicist and I've working with the Air Force since 2000."

"I'm Dr Carson Beckett, I'm a Medical Doctor and Geneticist and I've been working with Homeland Security since its inception in 2003."

"I am Teyla Emmagan and I'm a Special Consultant working with Homeland Security."

"I'm Ronon Dex and I'm also a Special Consultant working with Homeland Security."

"Thank you everyone!" Jack smiled, "I always think people work together a little better when we get to know each other that bit more…Anyways, Carter?"

Sam stood up and walked to the front of the room.

"Thank you sir, and thank you to Agent Gibbs' team. I'm sure you're very uncomfortable with our presence here. I know I would feel the same if the boot were on the other foot. I'm sure when you find out why we had to be involved, you will understand. Agent Gibbs has been fully briefed on the situation and both he and Director Vance have agreed to our involvement in this case.

"As I'm sure you'll also all very aware, there are a number of things happening within Homeland Security's remit that are never made public knowledge and that are not shared with our allies. For that reason I have to ask Agent David what country she is a citizen of."

Ziva seemed surprised at the question, "As of last month I am an American citizen."

Sam smiled, "That's good, otherwise I would have had to ask you to leave."

"Why?" Gibbs asked pointedly, "Dr Carson's Scottish and Abby Sciuto told me that McKay's Canadian."

"Politics," Sam smiled back in a tone that told Gibbs to leave that point alone.

"Moving on, one more aside," O'Neill started, "DiNozzo, you anything to Tony or Vincenzo DiNozzo? Both from Long Island?"

"Yeah, my dad's called Tony and one of my uncles is called Vincenzo."

"We'll need to catch up then if they're the same guys," he smiled, "anyway, Carter."

Sam shot her CO a less than professional look, annoyed at his interruption.

"As I was saying, Homeland Security often has to keep things from the general public, our allies, and sometimes also from our wider military – NCIS included. We believe that Timothy Danes and your Director were victims of a man who has been on the run from the Air Force for quite some time. This man has access to technology not yet released to the world, and unfortunately we are uncertain of his motivation. We should also tell you that not all of the technologies this man uses are conventional. They are in fact highly experimental and highly classified. This is where the unusual genetic readings originated, and this was why Dr. Beckett advised us of Ms Sciuto's findings."

"Thanks for that," Tony glared at the MD.

"You're welcome," Carson grumbled.

Sam continued, "This classified technology is what killed Danes. Why he did not try to kill Director Vance, we don't know. Nor do we know how Director Vance was rendered unconscious.

"Of top priority is tracking down the man we think is responsible, and unfortunately we will not be able to share his identity with you. We do however hope that he will leave behind a trail of electronic 'breadcrumbs'. Agent McGee I'm hoping you'll be able to help me track him down.

"Agent DiNozzo, Agent David, we're very much hoping that you will be able to help Sheppard, Teyla and Ronon track down this man on the ground."

Ziva, Tony, Sheppard, Teyla and Ronon all nodded in agreement.

"Agent Gibbs and Drs. McKay, Jackson and Beckett will remain here to liaise with General O'Neill and the commanders of Homeland Security."

Everyone in the room nodded in agreement with the exception of Vance who stared ahead blankly.

"I know you'll all have a lot of questions. We'll answer these to the best of our abilities as we go. Thank you."

Realising their 'briefing' was over, both teams rose and headed for the exit.

"DiNozzo," O'Neill called his name, "can we have that chat just now?"

Tony turned and wordlessly headed for the General.

"Uhm Sir," McGee asked, "Not to speak out of turn or anything, but I thought you'd want all of us to start on the case right away?"

"This will only take a second McGee," O'Neill said in a knowing tone, "I need to have a chat with this man with regards to his father."

Gibbs nodded, signalling that it was okay for his Senior Field Agent to remain behind, but as Gibbs watched Tony silently, and rather familiarly, walk towards the General, his gut began to work overtime.


End file.
